Burglar alarm



R. B. BURGLAR ALARM Filed June 1938 2 Sheets-Sheet June 2 III R. B.ESTES BURGLAR ALARM June 25, 1940.

2 Sheets-Sheet 2 Filed J n 1938 Patented June 25, 1940 PATENT OFFlCEBURGLAR ALARM Rufus B. Estes,

Knoxville, Tenn.

Application June 11, 1938, Serial No. 213,272

6 Claims.

This invention relates to an improvement in burglar alarms, and moreparticularly to an alarm used in connection with a window screen forresidence and apartment use, whereby an alarm will be given if anunauthorized person should try to enter the building by opening thescreen or cutting through the wire thereof.

The object of the invention is to provide for the closing of an electriccircuit to an alarm device by any tampering with the screen, upon theapplication of pressure against the outside of the screen wire, upon thecutting through of the screen wire, or the bodily removal of the screenfrom the window frame.

A further object of the invention is to improve the construction of aburglar alarm of this character, whereby it can be manufactured and soldat comparatively small cost and economically, because of its simpledesign, thus enabling the average home owner to use a burglar alarm inthe windows of his house for the protection thereof, with the assurancethat the device will function, even when it has been in place for asubstantial period of time.

In carrying out these objects, the invention utilizes the mounting ofthe screen wire resiliently in its screen frame with electrical contactsso arranged therebetween, as to close an electric circuit to theannunciator if the screen wire should be cut through or if the screenwire should be pressed outwardly or inwardly, or if the screen frameshould be unfastened and moved outwardly from its mounting in the windowframe for the purpose of removal. Provision is made by the mounting ofthe screen wire in its frame, whereby tampering with the wire itself orattempted removal of the screen will cause an alarm, which insurescomplete protection against an unauthorized entrance to a building atsuch a screened window or other opening with which this alarm is used.

I have illustrated one form of the invention in the accompanyingdrawings, in which:

Fig. l is a side elevation of a window screen from the inside of thebuilding embodying this invention with parts broken away to show theinterior construction thereof;

Fig. 2 is a horizontal sectional view through a side of the screenshowing one of the spring mountings thereof;

Fig. 3 is a partial bottom edge view of the screen frame showing theelectrical connections for the Wires;

Fig. 4 is a transverse sectional view through the electrical connectionsbetween the screen frame and the window frame of the building;

Fig. 5 is a vertical sectional view through one of the screen frameconnections substantially on the line 5-5 of Fig. 1;

Fig. 5 is an enlarged transverse sectional view through the bindingframe of the screen wire; and

Fig. '7 is a perspective view of one of the spring detents.

Fig. 1 shows a window screen removed from a window opening withoutillustrating the window frame or sill. The window screen illustratedutilizes a frame I, which may be constructed of wood or other suitablematerial and is shown as provided with the usual supporting hinges 2 atthe top thereof to engage hooks to be provided on the cooperating windowframe or casing for sup-porting the screen therein, the screen usuallybeing held in place at the bottom by a hook designated 3 which isattached to the window screen and engages an eye in the window sill.

As shown in Figs. 1 and 2, the screen frame I is recessed on its innerside at l, with a coacting groove 5 extending circumferentially in theframe I. The recess 4 is covered by a plate 0 which may be constructedalso of wood or of other suitable insulating material, which ispreferably the same as the insulating material forming the screen frameI.

.The screen wire is designated by the numeral 1 and is adapted to extendvertically throughout the inner area of the screen frame. The peripheralportion of the screen wire is enclosed preferably in a metal edging Bwhich is shown as formed of sheet metal, which should be of electricalconducting material, and having an offset shoulder 9, as shown in Fig.2. The binding edge 3 of the screen wire is slidable laterally betweenadjacent portions of the screen frame 9 and its inner cover 6 for bodilymovement of the screen wire relative to its supporting frame. The screenwire is held normally in a central position by a series of springs orother resilient means designated by the numeral l0 and which areconnected with the peripheral portions of the binding 8 outwardly of theshoulder 9. Openings ll are provided in the frame 5 to receive thesprings it, as illustrated, the outer end of each spring being attachedto a nail or other fastening 52 for securing the same to the screenframe I.

An electrical conducting wire 13 extends along the inner portion of thescreen frame I, adjacent the binding of the screen, and has nails orother contacting devices It attached thereto at intervals along theinner side of the shoulder 9 of the screen binding, normally in slightlyspaced relation from the shoulder ll out of contact therewith. However,upon the application of pressure to the screen wire '5, such as would becaused by the unauthorized pressing thereon or an attempt to out out thewire, the adjacent portion of the binding 3, which is preferablyflexible, will drawn against the adjacent contact device or devices itto close an electrical circuit b ween the contact material of thebinding and the wire it to close an electrical circuit to theannunciator. Orifices 55 may be provided at intervals in the binding 8to facilitate proper location and spacing of the contact device Mrelative to the adjacent portion of the shoulder El.

Mounted in the outer portion of the groove 5, preferably adjacent eachof the springs ii] is contact device it in position to be engaged by theouter edge of the screen binding ti, when pulled outwardly the spring itupon bodily devices comprises a movement of the spring wire or releasethereof, such as would be caused by cutting or other unauthorizedtampering therewith. The contact 56 are connected at ll with the wireit, to close an electric circuit to the annunciator through the wire 53upon either inward or outward movement of the screen binding 8, such swould be caused by the unauthorized tamperwith the screen.

intervals at the upper and lower portions of the screen frame, there areprovided additional contact devices adapted to close an electric cir--cuit if the screen frame should be opened relative to the window frame.Each of these contact contact strip of electrical .ng materialdesignated iii, which should spring material also, so as to flex awayfrom the screen frame upon removal of the latter from the window frame,such contact device f normally being held in position by the pressurebetween the screen frame and window frame.

The contact strip is overlies the cover plate 6, shown in Fig. 5, and.is secured thereto by rive screw, or other fastening 39, which attachess d contact strip 68 to the screen binding 8 for l electrical connectiontherebetween. One end of the strip ill, adjacent the rivet i9, is turnedinwa d to engage in the cover plate 6, to hold said end of the contactstrip in place.

The opposite end of the contact strip i8 is "J necl. inward at 2!through an orifice 22 in the same i, being loosely received in saidorifice for ii outward flexing relative thereto upon loosening t escreen frame from the window frame. The 1 ned nd H has an opening 23therein, as own in g, 7, through which opening a corn ct wire 2 2extends from its point of connection the conducting wire it, as shown inFig. 5. ms opening movement of the screen frame relative to the windowframe will allow flexure of one or more of the contact strips 18outwardly rel tive to the screen frame l, causing engaget between theperiphery of the opening 23 the wire 25, closing the electric circuitbetween. the wire it and the screen binding 8, ti rice to theannunciator for giving an alarm. Connected respectively with theconducting wire 2% with the screen binding 8 are connecting wires andwhich extend to electrical con-. tact plugs 2i and 28, respectively,carried by the screen. frame l in positions to engage in sockets i andmounted in the window casing, designated 35 in Fig. 4, Wires 32 and 33are connected with the sockets 29 and 38 and extend to a circuitcontaining a source of electrical supply and an annunciator, such as agong, bell, lights, etc., which annunciator will be energized upon theclosing of a circuit through the screen wire connections described abovefor giving an alarm of the tampering with the screen.

The mounting of the screen wire 7 in the frame for slight bodilymovement or yielding movement relative to the frame does not interferewith its effectiveness in screening against flies and other insects,rendering the screen completely fiyproof, in addition to its function asan alarm device.

I claim:

1. A circuit closure for a burglar alarm comprising a frame adapted tosurround a building opening, a sheet of screen wire within said frameadapted to cover said building opening, a binding strip enclosing theperipheral edges of the screen wire and having an ofiset shoulderportion, said frame having a groove receiving said binding strip, aplurality of springs attached to the frame and to the binding strip forstretching the screen wire over the opening, and circuit closing meanson opposite sides of said shoulder portion for closing an alarm. circuitupon relative movement of a portion of the screen and frame.

A circuit closure for a burglar alarm comprising a frame adapted tosurround a building opening, a sheet of screen wire within said. frameadapted to cover said building opening, a binding strip enclosing theperipheral edges of the screen wire and having an offset shoulderportion, said frame having a groove receiving said binding strip, aplurality of springs attached to the frame and to the binding strip forstretching the screen wire over the opening, contact devices arrai'igcdrespectively on opposite sides of the binding strip normally in spacedrelation therefrom in. posi tion to contact with said binding strip uponmovement thereof relative to the frame, and electrical conducting meansconnecting said contact devices together.

3. A circuit closer for a burglar alarm. comprising a frame adapted tosurround a building opening, a sheet of screen wire within said frameadapted to cover said building opening, a binding strip attached to anedge of the screen and ere tending laterally therefrom at an anglethereto, and contacts on respective opposite sides of the binding stripin position for engagement thereby.

i. A circuit closer for a burglar alarm comprising a frame adapted tosurround a building opening, a sheet of screen wire with said frameadapted to cover said building opening, a bind-- ing strip attached toan edge of the screen and extending laterally therefrom at an anglethere to, and contacts on respective opposite sides of the binding stripin position for engagement thereby respectively upon movement of thebind-- ing strip in either direction, a conductor connected with saidcontacts adapted to close an alarm circuit, and resilient means attachedto said binding strip tending to move the same in one direction.

5. A circuit closer for a burglar alarm. com-- prising a frame adaptedto surround a building opening, said frame having a recess therein, asheet of screen wire within said frame adapted to cover said buildingopening, a binding strip extending along respective opposite edges ofthe screen wire in the recess embracing the wire and attached thereto,said binding strip at each edge of the screen having a laterally offsetportion and an out-turned edge, resilient means attached to saidout-turned edge tending to move the same outwardly and stretch the wire,contacts on opposite sides of the laterally offset portion in positionsfor engagement thereby, and. a conductor connected with said contactsadapted to close an alarm. circuit when one of said contacts is engagedthereby.

6. A circuit closer for a burglar alarm comprising a frame adapted tosurround a building opening, said frame having a recess therein, a sheetof screen wire within said frame adapted to cover said building opening,a binding strip extending along respective opposite edges of the screenwire in the recess embracing the wire and attached thereto, said bindingstrip at each edge of the screen having a laterally ofiset portion andan out-turned edge, a plurality of coiled springs connected at oppositeends with the frames and out-turned edge of the binding strip tending tomove the same outwardly and hold the wire in place in the frame,contacts at the outer and inner sides of the laterally offset portion inpositions for engagement thereby, and a conductor connected with saidcontacts adapted to close an alarm circuit when one of said contacts isengaged thereby.

RUFUS B. ESTES.

